Background. Prevalence of hypothyroidism (HT) markedly differs among various populations. We aimed to establish the prevalence of HT in the Czech population and to assess its association with conventional cardiovascular risk factors. Methods and Results. 1240 subjects (629 m, 611 f; mean age 52.3); a random, population-based sample were evaluated. Cut-off points for thyroid parameters were defined as follows: thyreostimulating hormone (TSH) 0.58–3.65 mU/l, free thyroxine (fT4) 9–22 pmol/l and thyroid peroxidase antibodies (TPOAb) ≤14 IU/l. The overall prevalence of HT was 6.8 % in males and 13.8 % in females (p<0.0001); subclinical HT (high TSH, normal fT4) was found in 3.0 % and 8.0 %, overt-untreated (high TSH, low fT4) in 3.2 % and 3.0 % and overt-treated HT in 0.6 % and 2.8 % of males and females, respectively. Moreover, in euthyroid subjects, 4.6 % of males and 9.3 % of females showed positive TPO-Ab (p<0.0001). The adjusted relative risk of hypothyroidism was significantly increased in males with manifest vascular disease (odds ratio 3.48 (1.56–7.74)]), in females aged ≥ 55 years (2.08 (1.29–3.36)) or hypertension (1.80 (1.03–3.13)), and moreover, in males and females with positive TPOAb (5.81 (2.57–13.13) and 5.92 (3.38–10.36), resp.) Conclusions. Hypothyroidism was found in Czech population highly prevalent and it can contribute to the coronary risk, produced by conventional factors.

        Key words: thyroid, dysfunction, population, epidemiology, cardiovascular risk.